A branch-and-bound method for optimal design of microwave multilinks of electric power control systems

1977 ◽  
Vol 97 (5) ◽  
pp. 117-123
Author(s):  
Yoichi Kawai
Keyword(s):  
Optimal Design ◽  
Power Control ◽  
Electric Power ◽  
Control Systems ◽  
Branch And Bound ◽  
Branch And Bound Method

scholarly journals Method of improving the functional dependability of the control systems of an unmanned aerial vehicle in flight in case of failure in the onboard test instrumentation

Dependability ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 30-35
Author(s):  
D. V. Morozov ◽  
S. F. Chermoshentsev,
Keyword(s):  
Control Systems ◽  
Branch And Bound ◽  
Estimation Method ◽  
Functional Element ◽  
Diagnostic Model ◽  
Branch And Bound Method ◽  
Functional Component ◽  
Functional Efficiency ◽  
Test Instrumentation ◽  
Failure Location

The Aim of this paper consists in the development of a method of improving the functional dependability of the control systems of unmanned aerial vehicles (UAV CS) affected by electromagnetic effects in flight and failures within the functional component of the onboard test instrumentation (OBTI).That is achieved through the identification of the failed functional element, the functional component of OBTI, the capability of performing the target objective of the UAV CS and decision-making regarding the initiation of the flexible operation algorithm. The existing and future UAV CS under development use binary reliability models, i.e. two states are distinguished: up and disabled. Therefore, each in-flight failure is classified as the UAV CS failure regardless of the current mission. If we regard a CS as a multifunctional system, it becomes obvious that the failure of not any UAV CS functional element causes flight termination. Methods. Solving the problem involved the use of a CS diagnostic model in the form of binary relations between the control actions and combinatorial subsets of functional elements, risk of losses estimation method as part of improving the functional dependability of UAV CS in flight, decision theory and combined branch-and-bound method. The mission performance probability is used as the efficiency criterion. This criterion is applicable when changes in a UAV CS’ characteristics cause only partial reduction of the functional efficiency. Results. The purpose of CBTI self-supervision is failure location with the depth that allows determining its ability to perform the basic operations with the probability not lower than required by the customer, as well as the allowed set of elementary checks (EC) in this case. Based on the current results of elementary self-checks (ESC), one of the following decisions can be taken: stop the checks and discard CBTI; continue location; stop failure location and continue UAV CS mission per modified algorithm. At each stage of failure location in CBTI, based on the results of ESC, the area of covering check (ACC) and part of set suspected of failure (PSSF) are analyzed, which includes verifying the ACC for sufficient coverage of the PSSF, based on which appropriate decisions are taken. The following areas are formed: the area of observable data (processes of changes in the ACC and PSSF areas), within which the decision is taken to continue the checks, and the area, within which it is finally decided to terminate the checks. If It Is decided to continue the failure location, another ESC is selected, which Is associated with the risk of loss. The probability of false discarding of CBTI due to ESC selected out of ACC Is taken as the risk of loss. The moment of termination of CBTI self-supervision depends not only on the set of decisions, but their sequence as well. Thus, the task at hand comes down to designing the optimal ESC strategy that minimizes the probability of false discarding. The idea of combined branch-and-bound method (CBBM) as part of the design of the optimal CBTI self-supervision algorithm consists in the consecutive selection at each stage of ESC implementation process, out of the subset of minimum risk checks of the next ESC till a one-element subset is obtained and/or the corresponding decision is taken. Conclusions. The developed method allows continuing the performance of the target objectives of a UAV CS In flight when affected by failures In CBTI.

scholarly journals Algorithm and software for the optimal technological design of a system of simple distillation columns

2021 ◽  
Vol 16 (5) ◽  
pp. 379-389
Author(s):  
N. N. Ziyatdinov ◽  
I. I. Emelyanov ◽  
A. A. Ryzhova ◽  
P. S. Chernakov
Keyword(s):  
Optimal Design ◽  
Branch And Bound ◽  
Software Package ◽  
Distillation Column ◽  
Mixed Integer ◽  
Branch And Bound Method ◽  
Simple Distillation ◽  
Technological Design ◽  
Distillation Columns ◽  
Aspen Hysys

Objectives. The formalized problem of the optimal design of distillation column systems belongs to the class of mixed integer nonlinear program problems. Discrete search variables are the number of trays in the rectifying and stripping sections of columns, whereas the continuous ones are the operating modes of columns. This study aimed to develop an algorithm and a software package for the optimal technological design of a system of simple distillation columns based on the criterion of total reduced capital and energy costs using rigorous mathematical distillation models.Methods. The solution to this problem is based on the branch and bound method. A computer model of the distillation column system was developed in the environment of the Aspen Hysys software package. The Inside–Out module was used as the distillation model. The developed algorithm is implemented in the software environment of the Matlab mathematical package. To solve the conditional optimization problem, a sequential quadratic programming method-based model was used. The interaction between software add-ins in Matlab and Aspen Hysys is implemented using a Component Object Model interface.Results. Approaches to obtain the lower and upper bounds of the optimality criterion and the branching method for the implementation of the branch and bound method have been developed. In addition, an algorithm for the optimal design of a distillation column of a given topology based on the branch and bound method has been developed. Furthermore, using Matlab, a software package that implements the developed algorithm and is integrated with the universal modeling software AspenHysys has been created.Conclusions. An algorithm and a software package have been developed and implemented that allows automating the design process of distillation column systems and integration with advanced mathematical programming packages, respectively. The performance of the algorithm and software package has been evaluated using the optimal design of the debutanization column as an example.

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